Control mechanism for intermittent gas refrigerators



F. J. BAST Jan. 22', 1935.

CONTROL MECHANISM FOR INTERMITTENT GAS REFRIGERATORS 2 sheets-Sheet@ led July l5, 1932 INVENTOR F /m/v/f J. B/ls r BY fik-MIM ATTORNEYS Jan. 22, 1935. F. J. BAST n 1,988,774

CONTROL MECHANISM FOR INTERMITTENT GAS REFRIGERATORS Filed July 13, 1932 2 sheets-'sheet 2 INVENTOR F/P/l/v/(J 5,45 r

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f Nm. N ww z w. v .eww .Q H zmm. @WN f E ma. mm R mm. wh. i2.. GWA@ Mm, S S n f T ,w N W n fl 1l 1v1 Patented Jan. 22, 19.35

CONTROL MECHANISM FOB TENT` GAS REFRIGERATOBS Frank Bast, Queens Village, N. Y., assignor to Charles J. Tagliabue Mfg. Co., Brooklyn, N. Y.,

a corporation of New York Application July 13, 1932, Serial No. 622,333

" 20 Claims. (CI. 236-39) The present invention relates to mechanism for 'controlling the operation of a gas refrigerator,

y and particularlyone of the intermittent type, in

Y order to maintain continuously a temperaturein 5 the refrigerator which is not above a predetermined maximum temperature.

, In the intermittent type 'of gas'refrigerator, the

a ,Sblublegas actingv as a refrigerant is dissolved in wateror some other solvent, and the solvent then 10 "heated 'to a temperature such that substantially all ofthe refrigerant is driven ofi'. The expelled refrigerant issimultaneously liquefied by cooling under the pressure developed by the boiling. When the boiling temperature reaches a predetermined point, the gas is turned off, whereupon the boiling portion of the cycle is terminated and the refrigerating period then begins as the liquid refrigerant is fed through a fixed orifice into the expansion coil or chillerator, such feeding and refrigerating continuing until all of theliquid has been evaporated. The vapor is redissolved in the solvent as quickly as it is formed until at the end of this portion of the cycle practically all of the refrigerant has been absorbed by the solvent. The gas is then turned on lagain and the solvent heated to drive. olf the vapor under pressure which is then condensed as described above, and

the cycle is thus repeated. The cycle of the intermittently operating gas refrigerator has usually been controlled manually, the gas valve being permittedto remain open for, say, about three hours to effect driving off of the refrigerant vapor under pressure, after which the gas is turned off; the cooling cycle then con- 35 tinues for about eight hours, after which the gas is again turned on and 'allowed to drive off the absorbed refrigerant from the solvent. This method of hand control is troublesome and subv ject to delays and omissions which militate 40 against' the maintenance of a uniformly low temperature in the refrigerator.

It is the object of the present invention to prog vide mechanism for automatically controlling the operationsof an intermittently operating gas refrigerator by automatically controlling the flow of gas to the burner of the boiler. It is a further object of the invention to provide a control mechanism which operates with a snap action so that the feed of gas to the atmospheric Bunsen burner 50 of the boiler may be started and stopped with extreme rapidity. It is also an object of the invention to provide a control mechanism of the type indicated whichis simple and inexpensive in construction and reliable in operation. It is a. still further object of the invention to provide a control mechanism for intermittently operating gas refrigerators which is capable of adjustment to vary the temperatures at which the heating cycle is begun and terminated in order to insure the maintenance of a predetermined low temperature in the refrigerator and of safe operating conditions in the boiler.

Other objects will be apparent from the followingdescription and the features of novelty will be set forth in the appended claims.

According to the present invention the ilow of ygas to the boiler of the refrigerator is controlled by a suitable regulating device, such as a valve, which is in turn under the influence of two separate thermostaticsystems. One of these systems, the heat control system, is responsive to temperature changesinthe boiler of the refrigerator; while the other or cold control system is responsive to fluctuations in the temperature of the chillerator or 'other cold part of the refrigerator. As it is 20 highly desirable that the flow of gas to the boiler be started or stopped very quickly, I make the valve controlling element in the form of a snap device, and so arrange the thermostatic elements that they produce opposite effects upon such snap device; that is, rise of the temperature in the boiler to a predeterminedmaximum causesthe associated thermostat to effect movement of the snap device in one direction, while rise of the temperature in the chillerator to a predetermined maximum effects operation of this snap device in the opposite 'r direction. Means are also provided to shut of! completely the flow of gas independently of thethermostatic mechanisms when the temperature in the boiler for any reason rises to a dangerous 3g height. Y

A preferred embodiment of the invention is illustrated by way of example on the accompanying drawings, wherein Fig. 1 is a central section through the control 40 mechanism along the plane l--l of Fig. 2

Fig. 2 lis aplan view of the mechanism with part of the casing removed;

Figs. 3 and 4 represent sections on an enlarged scale taken along the planes 3-3 and 4 4, re- 45 spectively, of Fig. 2;

Fig. 5 is a top view of the snap switch mechanism; and

Figs. 6 and 7 are front views illustrating different positions of the structure shown in Fig. 5.

r Referring to the drawings, the control mechanism is housed within anv air tight casing consisting of a body portion 10, a cover 11, and a back plate 12, the cover and plate being removably xed to the body portion 10 in any suitable 55 manner, as by means of screws 13. Packings 14 may be interposed between the parts to insure a gas-tight joint.

The body 10 of the casing is provided with a transverse web 15 dividing the interior of the casing into two sections or compartments 16 and 17. The web 15 is provided with a bore 18 communicating with an inlet connection 19 (see Fig. 2) to which the gas line is adapted to be attached. The bore 18 leads to a transverse port 20 opening into the compartment 16 (Fig. 1).

A through port 21 in the web 15 connects the compartments 16 and 17. The web 15 is provided also with a port 22 (Fig. 3) leading into the bore 22a, communicating with the outlet 23 which is adapted to beconnected to a gas line leading to the burner under the boiler. The outlet port 22 is controlled by a valve 24 loosely mounted upon a spring arm 25 whose opposite end is xed to the web 15, as shown at 26. The tension in the spring arm 25 is such that the valve 24 is normally urged away from the port 22 to permit any gas entering the casing through inlet 19, bore 18, and port 20, and passing into space 17 vfrom space v16 through the bore 21, to flow through port 22, bore 22a and outlet 23 to the boiler.

lThe valve 24 is controlled preferably by means of a snap mechanism which, in the embodiment of the invention illustrated, is shown as being in the form of a snap toggle mechanism. This mechanism comprises a long plate 27 (Figs. 1, 6 and 7) and a short plate 28,.which pivotally engage each other in abutting relation, the short plate 28 being provided with a knife edge which engages between the two upwardly bent lateral ears'29 and the downwardly bent middlev portion 30 of plate 27. At their outer. ends the plates 27 and 28 engage `resilient supporting members 31, likewise along knife edges. The supporting members 31 are riveted to a flexible plate 32 whose ends rest upon bosses 33 on the web 15, so that the main portion of the plate 32 is spaced from the web. The plate 32 is held in position by means of screws 33a which may be adiusted to flex the plate 32 and thereby increase the resistance of the-resilient supports 31 against a force tending to place the tQggle plates 27 and 28 in alignment. l

The plate 27 is provided lwith an adjustable screw 34 arranged to engage the spring arm 25` as can best be seen in Figs. 1 and 3. The downwardly extending middle portion 3 0 of the plate I 27 engages within a slot in the supporting plate 31 and operates tollimit the movement of the snap mechanism in both directions, as is described in greater detail in my co-pending application vSerial No. 548,520. i

It will be seen from the above that when the snap mechanism 27, 28 is in its lower position as shown in Figs. 1 and 3, the valve 24 is closed and no gas flows tothe boiler. -The parts are thus in the position which they occupy during the cooling or expansion portion of the cycle in which. the accumulated condensed refrigerant is being slowly discharged through an orifice into the expansion coil to cool the refrigerator, the expanded and warmed refrigerant being then reabsorbed by the solvent. As soon as the supply of condensed refrigerant is exhausted and the temperature in the refrigerator tends to rise above the predetermined maximum, it becomes necessary to start the ilow of gas to the boiler. This is accomplished with the aid .of a' cold control thermostatic system comprising bellows 35 connected with a thermostatic bulb 36 positioned in the chillerator (or other cold part) of the refrigerator. As soon as the temperature in the chillerator has risen to a predetermined point,

the bellows 35 is expanded sulciently for its stem' 37 to tilt the angular arm 38'mounted upon the short plate 28 of the snap mechanism, causing such plate to snap into its upper position as shown in Fig. 7. In this upper position the screw 34 is removed from the spring arm 25, which thereupon opens the valve 24 and permits the' its stem 41 engages and presses upon the plate 27. The latter is thus forced downwardly into the neutral plane, whereupon the toggle mechanism snaps into the reverse position shown in Figs. 1 and 6. The gas valve 21 is thereupon closed and the supply of gas to the boiler ceases. The angular arm 38 (Figs. 1, 5, 6 andl 7) is ivoted at 42 upon the U-shaped bracket 43 iixed to the short plate 28 and is normally held in the full line position shown in Fig. 5 by a wire spring 44. The free end of the arm 38 is guided within a loop 45 in an arm 46 which is ilxed to the other leg of the bracket 43. The arm 46 may serve also tol anchor the spring 44, as illustrated in Figs. 5,*6 and 7.

It will be understood that the boiler is providedy with a pilot light which serves to ignite the gas owing thereto as soon as the valve 24is opened.V During the boiling portion ofr the cycle the stem 37 is in its lower position because the bellows 35 has become expanded upon rise of temperature in the food chamber or chillerator. The parts are so designed that when the beveled lower end of stem 37 is in its lower position and the toggle mechanism is in the'position shown in Fig. 7, the arm 38 will clear the lower end ofv stem y37 when the toggle mechanism returns to the position shown in Fig. 6. In thelatter position the arm 38 has been forced to swing intov the position shown in dotted lines in Fig. 5.by the engagement with the side of -the stem 37. When the temperature in the'food chamber falls during the cooling cycle- (the boiler being no longer in operation) the bellows 35' contracts and the stem 37 moves upwardly (by mechanism to be described hereinbelow) until it clears the arm 38, whereupon the latter swings into lthe position shown in full-lines in Fig. 5 and'con'ies directly under the stem 37 'as shown in Figrl.` Upon subsequentlexpansion of the bellows 35, the arm 38 is in a position tovvbe directly engaged by the stem to causethe toggle mechanism 4to snap into the condition shown in Fig. 7. V

The stem 41' is riveted 'or otherwise fixed to one end of a lever 47 (Fig. V4) pivoted intermediate' its ends at 48- upon spaced ears 49 struck from a plate 49a supported by four standards 50 screwed` threaded-end of a screw 55.threaded into an internally and externally threaded bushing 56, the screw and bushing being covered by a cap 57 to render the joints air-tight. It will be seen that the bellows 40 upon expansion will move the stem `41 downwardly against the action of spring 53 and upon contraction of the bellows the stem is caused to follow the movement of the bellows by the spring pressed lever 47. By the selective adjustment of the screw the temperature in the boiler at which the toggle mechanism is caused to close the gas valve 24 may be regulated.

'Ihe stem 37 of bellows 35 is similarly provided with a lever 47a pivoted intermediate its ends upon the plate 49a and engaged at its other end by a plate 52a against which bears one end of a spring 53a, whose other end engages a plate 54a. A screw 55a similar to the screw 55 engages the plate 54a and is screwed into a bushing 56a and covered by a cap 57a. The stems 37 and 41 pass through openings in the plate 49a and are guided therein. 'I'he stems are provided with enlarged shoulders 58, .58a which serve as stops and prevent movement of the stems beyond a definite limit. In this wayA the toggle mechanism is protected against injury through excessive expansion movement of the bellows 35 and 40.

In order to enable the boiler to be started when the gas valve 24 is closed, I have provided a manually operable plunger 59 controlled by a Ypush button 60 upon the outside of the casing and normally held against its seat 61 by a spring 62. Upon depression of the button 60 the plunger 59 is moved inwardly and engages an arm 63 xed to the smaller toggle plate 23r and operable upon movement of its free end to tilt the toggle plate upwardly and thereby cause snapping of the toggle mechanism to the position shown' in Fig. 7 inwhich the gas valve 24 is open.

To prevent rise of tempera-ture in the boiler beyond a safe maximum I provide 'a safety mechanism in the form of a valve member 64 arranged opposite the gas port 20. The valve 64 is swiveled to a rod 65 located within a tube 66 which is constricted at 67 to provide a seat for a spring 68 engaging a collar 69 on the rod. The tube 66 is secured in gas-tight manner to the casing, as by soldering or brazing, as shown at 66a. The opposite end of the tube' and rod are soft soldered to each other as shown at 70, such end being adapted to be placed within the boiler. Upon rise of the temperature in the boiler beyond a predetermined maximum, the solder is melted and the rod 65 is moved inwardly of the casing l0 by the spring 68, until the port 20 is closed by the valve 64. therefore, pressure upon button 60 fails to start the apparatus, it will be evident to the operator that the valve 64 has been released to close the port 20 and that some defect has occurred in the'sboiler.

As can be seen from Fig. 1, the bellows 35 and 40 may be fixed within the casing by means of threaded extensions 71, 71a, passing through suitable openings in the wall of the casing and clamped to the later by nuts 72, 72a.

'I'he operation of thercontrol mechanism will be clear from the above description and may be As already stated,

briey described as follows: the gas enters at 19 and passes through bore`18 and port 20 into the compartment 16 from which it ows through opening 21 into compartment' 17. From the latterit passes through valve controlled port 22 into the bore l22a and nally leaves the control mechanism through the outlet 23. It the valve 24 is closed, and it is desired to start the apparatus, the button 60 is depressed tolcause the plunger 59 to engage the angular arm 63 and swing the latter to bring the snap I verse position shown in Fig. 6, whereupon the valve 24 is closed. During the boiling cycle the stem 37 is in its downward position,i. e. its righthand position as viewed in Fig. 7, so that when the toggle mechanism is snapped tothe right to close the valve, the angular arm 38 swings leftwardly and engages the upperl side of the stem.

37, the arm taking the position-shown in dotted lines in Fig. 5. The cooling cycle will now begin, and both the bellows 35 and 40 will contract.

Before the chillerator or cold unit has reached its lowest temperature, the bellows 35 will have contracted suiriciently to permit thearm 38 to swing under the stem 37, so that when the bellows 35 again expands, the arm will be engaged by the stem.

springs 53, 53a are arranged in juxtaposition at one end of the casing approximately at theV four corners of a quadrilateral and with their axes perpendicular to the plane of such quadrilateral. This arrangement not only produces a very compact construction but enables the bellows and springs tobe all mounted upon the same end wall ofthe casing, which is advantageous from the standpoint of easierassembly and accessibility.

Parts of my invention may be used without `others and variations may be resorted to within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In a control mechanism for vgas-heated refrigerators, particularly for Arefrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrigerator compartment, the combination of 4a gas-tight casing having an inlet and an outlet adapted to be connected, respectively, with a source of gasand with the burner of the boiler, said inlet normally delivering gas into the interior of the casing for discharge through the outlet, a valve within the casing controlling the flow of gas therethrough, mechanisms positioned in the gas space in said casing and separately responsive to dhanges in the temperature in the l boilerand in the refrigerator, and meansassocated with said valveand operated conjointly by said mechanisms to effect opening and closing of the valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a predetermined value.

2. In a control mechanism for gas-heated re` frigerators, particularly for refrigerators operating on acycle including a heating period in the boiler followed by a cooling Aperiod in the refrigerator, the combination of I a gas-tight casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, a valve within the casing controlling the flow of gas therethrough, two bellows `positioned within the gas space in said casing andadapted to be connected respectively with thermostatic bulbs positioned in the refrigerator and in the boiler, a spring associated with each bellows and disposed in said casing,

It will be noted that the bellows 35, 4o and the 3. In a control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrigerator, the combination of a casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the "burner of the boiler, a valve controlling the flow of gas between said inlet and outlet, mechanisms in said casing separately responsive to changes in the temperature in the boiler and in the refrigerator, and means associated with said valve and operated conjointly by said mechanisms to effect opening and closing of the valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a predetermined value, said means comprising a togglel device including two abutting elements adapted to snap into opposite positions, said responsive mechanisms being arranged upon the same side of the toggle device and exerting pressure in the same direction as said temperatures increase, one of said mechanisms engaging one element of the toggle device and the other mechanism the other element of said device to throw thel latter into its opposite positions at said respective predetermined temperatures.

4. In a control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrig-- erator, the combination of a casing having an inlet and outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, a valve controlling the flow of gas from the inlet to the outlet, mechanisms in said casing separately responsive to changes in the temperaturein the boiler and in the refrigerator, and means associated with said valve and operated conjointly by said mechanisms to effect opening and closing of the valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a predetermined value, said means comprising two plates disposed in pivotal relation at their inner ends and normally arranged angularly with respect to each other, and spring means urging said plates toward each other.

5. 'I'he combination as set forth in claim l, including safety valve mechanism comprising a spring-pressed valve held in the open position by a body of solder upon the stem thereof adapted to be positioned in the boiler and to become fused when the temperature in the boile'r tends to rise above a predetermined safe maximum, said valve thereupon moving to closed position to stop the flow of gas through the casing.

6..In a controlmechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrigerator, the combination of a casing having lan inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, a valve controlling the ow o1.' gas from the inlet to the outlet, mechanisms in said casing separately responsive to changes in the temperature in the boiler and in the refrigerator, means associated with said valve and operated conjointly by said mechanisms to effect opening and closing of the Valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a predetermined value, and means manually operable to open the said valve to settheboiler and refrigerator into operation. f

7. In a control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrig- *erator compartment, the combination of a gastight casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, said inlet normally delivering gas into the interior of the casing for discharge through the outlet, a valve within the casing controlling the flow of gas therethrough, a pair of thermostatic bellows positioned within the gas space in said casing and responsive, respectively, to changes in the temperaturev in the boiler and in the refrigerator, a pair of levers pivoted within said casing, each lever being engaged by one of said bellows, spring means acting against said levers and opposing the movement of the bellows in one direction, said bellows and spring means being all located at one end of the casing, and means associated with said valve and operated conjointly by said bellows to effect opening or closing of the valve when the temperature in the refrigerator or in the boiler, respectively, has risen to a predetermined value.

8. In a control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrigerator, the combination of a casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, a valve controlling the ilow of gas from the inlet to the outlet, a pair of ther-V mostatic bellows in said casing responsive, respectively, to changes in the temperature in the boiler and in the refrigerator, and means associated with said valve and operated conjointly by said bellows to effect opening and closing of the valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a predetermined value, said means comprising two toggle members disposed in pivotal relation at their inner ends and pivotally mounted at their outer ends, one of said members having a portion extending beyond its outer pivot, .and spring means urging said members toward each other, said bellows being arranged at the same side of the toggle members, one bellows acting upon said extending portion and the other upon the other member to cause snapping of the toggle members in opposite directions.

' 9. The combination as set forth in claim 'I wherein the bellows and spring means are mounted upon the saine end wall of the casing, the mounting for said spring means including screws passing through the said end wall and accessible from the exterior of the casing for adjusting the pressure of said springs means.

10. In a control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler follower by a cooling period in the refrigera- -tor space, the combination of a casing having an -inlet and an outlet adapted to be connected, re-

spectively, with the source of gas and with the boiler and in the refrigerator, a pair of levers pivoted within said casing and each engaged by one of said bellows, springs engaging the said leversand opposing the movement of the associated bellows in one direction, and means associated with said valve and operated conjointly by said bellows to effect opening and closing of the valve when the temperature in the refrigerator and in the boiler, respectively, has risen to a pre- Vdetermined value, said levers being pivoted intermediate their ends, said springs being compression springs, and each `bellows and spring `bearing upon opposite ends of the associated lever.

11. In a control mechanism for gas-heated refrigerators, particularly for refrigerators oper ating on a cycle including a heating period in the boiler followed by a ,cooling period in the refrigerator, the combination of a casing, a web in said casing dividing the same into two compartments, said casing having an inlet and an outlet adapted to be connected, respectively, Awith a source of gas and with the burner of the boiler, said web provided with a bore leading from4 said inlet into one of said compartments, and with a through bore connecting the two compartments, and having a third bore leading from the second compartment to said outlet, a valve controlling one of said bores, a spring arm supporting said valve and adapted normally to hold said valve in raised position, snap mechanism associated with said valve and operative in one position thereof to force the `valve to the, closed condition and in its opposite position to permit the valve to be opened by its spring arm, and mechanisms in said casing separately responsive to changes.

in the temperature in the boiler and in the refrigerator and arranged to cause said snapping mechanism to move into the one or the other of its limiting positions as the temperature in the boiler or the refrigerator, respectively, reaches a predetermined maximum.

12. The combination as set forth in claim-1l, 4wherein said valve controls a bore other than the first bore, and including a second valve associated with such flrst bore, and means effective when the temperature in the boiler rises vbeyond a predetermined safe maximum to causey said second valve to close the said first bore, whereby the flow of gas to the outlet of the casing is cut olf 'independently of the first mentioned valve.

13. Ina control mechanism for gas-heated refrigerators, particularly for refrigerators operating on a cycle including a heating period in the boiler followed by a cooling period in the refrigerator, the combination of a casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, a conduit in said casing for leading to the outlet the gas admitted through said inlet, a valve controlling said conduit, a snap mechanism associated with said valve to control the vopen and closed positions thereof, said mechanism comprising a pair of plates disposed in pivotal relation at their inner ends and normally arranged angularly with respect to each other, spring means urging said plates toward each other, thermostatic mechanism arranged to exert pressure upon one of said plates and including an expansible bellows and 'a thermostatic bulb adapted te be positioned within the toner, a

second thermostatic mechanism arranged to exert pressure upon the other plate and including an expansible bellows and a thermostatic bulb adapted to be positioned within the refrigerator, and aspring associated with each of said bellows and arranged to oppose the pressure thereof.

,14. The combination as set forth in claim 13, including a plunger movable to move the snap mechanism to the position in which said valve is open, and a push button arranged upon the outside of the casing and operable to force said plunger inwardly.

15. The combination as set forth in claim 13, whereinsaid spring means comprise resilient supports upon which the outer ends of the plates are pivotally mounted, said combination including an arm pivoted upon the plate associated with the second-mentioned bellowsand extending beyond the outer pivot of such plate, a stem arranged between such bellows and said arm, the arrangement being :such that said arm normally underlies said stem so as to be engaged thereby upon expansion of said second mentioned bellows but is clear of said stem when the snap mechanism is swung into its opposite position to permit further expansion of said second mentioned bellows, said arm adapted to engage said stem and be swung out of its normal position upon return of the snap mechanism to its original position, and a spring urging said arm into its normal position. f

16. The combination as set forth in claim 13, wherein said spring means comprise resilient supports upon which the outer ends of the plates are pivotally'mounted, said combination including an' arm pivoted upon the plate lassociated with the second mentioned bellows and extending beyond the outer pivot of such plate, a stem arranged between such bellows and said arm, the arrangement being such that said arm normally upon expansion of said second mentioned bellows but is clear of said stem when the snap mechanism is swung -into its opposite position to permit further expansion of said second mentioned bellows,

said arm adapted to engage said stem and be swung out of its normal position upon return of the snap mechanism to its original position, a spring urging said arm into its normal position, said plate having an angular arm xed thereto,

and `means operable from the exterior of the cas-` ing to engage said angular arm to move the snap mechanism from the position in which the valve is closed to the opposite position. f

17. In a control mechanism for gas-heated rerespectively, with the boiler and with the expansion apparatus, said mechanisms arranged to be operative on said valve to urge the same toward the opening or closing position as the temperature in the expansion apparatus or in the boiler rises to a predetermined value, and manually operable ,means accessible from the exterior of the casing for opening the valve to start the refrigeratorin operation. 18. In a control mechanism forges-heated refrigerators, particularly for refrigerators operaton a cycle including a heating period in the boiler followed by a cooling period in the refrigerator compartment, the combination of a gas- 40. underlies said stem so as to be engaged thereby tight casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler, said inlet normally delivering gas into the interior of the casing for discharge through the outlet, a valve within the casing controlling the ow of gas therethrough, mechanisms positioned in the gas space in said casing and separately responsive to changes in the temperature in the boiler and in the refrigerator comprising a'pair of bellows positioned within said casing, a spring associated with each bellows and arranged to oppose the movement thereof in one direction, said bellows and springs being arranged in juxtaposition at one end of the casing approximately at the four corners of a quadrangle and perpendicular to the plane of the latter, means passing through one wall of the casing and operable from the exterior thereof for adjusting the pressure of said springs, and meansl associated with said valve and operated conjointly by said mechanisms to effect opening or closing of the valve when the temperature in the refrigerator or in the boiler, respectively, has risen to a predetermined value.

19. In a control mechanism for gas-heated refrigerators, the combination of a gas-tight casing having an inlet and an outlet adapted to be connected, respectively, with a source of gas and with the burner of the boiler of the refrigerator, a valve controlling the flow of gas through the'casing, snap mechanism associated with said valve to control the open and closed positions thereof, a plate mounted within the casing, a pair of thermostatic bellows positioned at one side of said plate and separately responsive to changes in the temperature in the boiler and in the refrigerator space, springs located within the casing upon the same side of the plate as said bellows and arranged to oppose the movement of the respective bellows in one direction, a lever associated with each bellows and its spring, said levers being pivotally supported upon said plate, said snap mechanism being arranged upon the opposite side of said plate, and means moved by said bellows to cause actuation of said snap mechanism in one or the other direction to eiect opening or closing of the valve as the temperature in the refrigerator or'in the boiler, respectively, reaches a predetermined maximum.

20. In a control mechanism for gas-heated refrigerators comprising a boiler and an expansion apparatus for the refrigerant, the combination of a casing, a conduit for delivering fuel to said boiler, a valve controlling said conduit, two sensitive mechanisms in said casing adapted to be associated with the boiler and with the expansion apparatus, respectively, for response to fluctuation in the temperature or pressure therein, said mechanisms arranged to be operative on said valve to urge the same toward the opening or closing position as the temperature in theexpansion apparatus or in the boiler rises to a predetermined value, and manually operable means accessible from the exterior of the casing for operating said valve independently of the condition of said responsive mechanisms.

` FRANK J. BAST. 

